Bears out D.P. Davies comments in Handling the Big Jets that whilst actual stalls are low probability on jets, stall warnings are more like 1 in 100,000 flights (working on memory here) so very important for pilots to have regular training in recognition and recovery.
If the evidence that we have been presented with is correct then there was clearly a lack of monitoring. Never mind Vref - 40, the mere fact that the speed is Vref or a tad below should have got the PM (and the safety pilot) shouting AIRSPEED!!
No level of automation and/or failure modes is going to keep you out of trouble for ever. We are talking BASIC AIRMANSHIP here - SOMEBODY has to be "minding shop".